<?php

require_once 'HTMLPurifier/AttrDef.php';

/**
 * Framework class for strings that involve multiple values.
 * 
 * Certain CSS properties such as border-width and margin allow multiple
 * lengths to be specified.  This class can take a vanilla border-width
 * definition and multiply it, usually into a max of four.
 * 
 * @note Even though the CSS specification isn't clear about it, inherit
 *	   can only be used alone: it will never manifest as part of a multi
 *	   shorthand declaration.  Thus, this class does not allow inherit.
 */
class HTMLPurifier_AttrDef_CSS_Multiple extends HTMLPurifier_AttrDef
{
	
	/**
	 * Instance of component definition to defer validation to.
	 */
	var $single;
	
	/**
	 * Max number of values allowed.
	 */
	var $max;
	
	/**
	 * @param $single HTMLPurifier_AttrDef to multiply
	 * @param $max Max number of values allowed (usually four)
	 */
	function HTMLPurifier_AttrDef_CSS_Multiple($single, $max = 4) {
		$this->single = $single;
		$this->max = $max;
	}
	
	function validate($string, $config, &$context) {
		$string = $this->parseCDATA($string);
		if ($string === '') return false;
		$parts = explode(' ', $string); // parseCDATA replaced \r, \t and \n
		$length = count($parts);
		$final = '';
		for ($i = 0, $num = 0; $i < $length && $num < $this->max; $i++) {
			if (ctype_space($parts[$i])) continue;
			$result = $this->single->validate($parts[$i], $config, $context);
			if ($result !== false) {
				$final .= $result . ' ';
				$num++;
			}
		}
		if ($final === '') return false;
		return rtrim($final);
	}
	
}

